Heartbleed Bug is a serious flaw in the OpenSSL cryptographic library
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2014-0160 | Heartbleed: unauthenticated memory disclosure in OpenSSL TLS/DTLS heartbeat handling The flaw (CVE-2014-0160, widely known as 'Heartbleed') is an out-of-bounds read (CWE-125) in the TLS and DTLS implementations of OpenSSL, caused by improper handling of Heartbeat Extension packets. A remote, unauthenticated attacker triggers it by sending a crafted heartbeat request whose declared payload length exceeds the data actually sent, causing OpenSSL to copy up to roughly 64 KB of adjacent process memory into the response. The attacker gains chunks of process memory per request — potentially TLS private keys, session cookies, usernames and passwords — and can repeat the request to harvest more, typically without any trace in logs. Any server or client running a vulnerable OpenSSL release that enables TLS or DTLS heartbeats is affected, which at the time of disclosure included hundreds of thousands of internet-exposed HTTPS servers as well as appliances, load balancers, and bundled libraries. Exploitation is confirmed in the wild: the vulnerability is listed in CISA KEV (added 2022-05-04, required action: apply updates per vendor instructions) and EPSS assigns it the maximum 100% probability of exploitation within 30 days. Do: Apply OpenSSL updates per your OS or vendor's instructions — the upstream fix at the time of the 2014 disclosure was OpenSSL 1.0.1g, with most distributions shipping backported patches — and restart or rebuild every service linked against OpenSSL, including bundled copies in load balancers, appliances, and VPN or management interfaces. Because leaked memory can include TLS private keys, treat keys and certificates on affected endpoints as compromised: rotate keys, reissue and revoke certificates, and invalidate session cookies and credentials that may have leaked. Confirm the heartbeat fix is present on all TLS/DTLS endpoints to satisfy the CISA KEV required action. | — | 100% | KEV |
| mass≈500,000+ internet-exposed HTTPS servers at the time of disclosure, plus vastly larger embedded/library deployments |
Full article676 words · extracted from securityaffairs.com · click to collapse
The Heartbleed Bug is a serious flaw in the popular OpenSSL library that allows an attacker to reveal up to 64kB of memory to a connected client or server.
Experts which provide maintenance to OpenSSL library have patched a serious vulnerability (CVE-2014-0160) that allows an attacker to gain the access to 64 KB of memory to any client or server that was connected.
“The Montgomery ladder implementation in OpenSSL through 1.0.0l does not ensure that certain swap operations have a constant-time behavior, which makes it easier for local users to obtain ECDSA nonces via a FLUSH+RELOAD cache side-channel attack,” reports the CVE record for the vulnerability.
The OpenSSL project is managed by a worldwide community of volunteers, which provides support OpenSSL library and related documentation. OpenSSL is the most popular open source cryptographic library and TLS implementation for traffic encryption.
“Bugs in single software or library come and go and are fixed by new versions. However this bug has left large amount of private keys and other secrets exposed to the Internet. Considering the long exposure, ease of exploitation and attacks leaving no trace this exposure should be taken seriously.”
The OpenSSL community hasn’t provided a detailed info on the fixed flaw, below an abstract from the release notes 1.0.1g:
“A missing bounds check in the handling of the TLS heartbeat extension can be used to reveal up to 64kB of memory to a connected client or server,” states the OpenSSL release notes for 1.0.1g.
The OpenSSL library is present in a wide variety of OSs as well as applications and most popular web servers including Nginx and Apache.
Which version of the OpenSSL are affected?
- OpenSSL 1.0.1 through 1.0.1f (inclusive) are vulnerable
- OpenSSL 1.0.1g is NOT vulnerable
- OpenSSL 1.0.0 branch is NOT vulnerable
- OpenSSL 0.9.8 branch is NOT vulnerable
Bug was introduced to OpenSSL in December 2011 and has been out in the wild since OpenSSL release 1.0.1 on 14th of March 2012. OpenSSL 1.0.1g released on 7th of April 2014 fixes the bug.
Security experts at Codenomicon prepared an interesting list of FAQ on the vulnerability, dubbed the Heartbleed flaw, which allows an attacker to remotely read the memory of a machine that runs a vulnerable version of the library.
“The Heartbleed bug allows anyone on the Internet to read the memory of the systems protected by the vulnerable versions of the OpenSSL software. This compromises the secret keys used to identify the service providers and to encrypt the traffic, the names and passwords of the users and the actual content. This allows attackers to eavesdrop communications, steal data directly from the services and users and to impersonate services and users,” is reported on an official FAQ page.
The flaw, which is considerable a programming mistake, also impacted cloud computing platforms including CloudFlare that already implemented its own fix for the OpenSSL vulnerability last week.
“OpenSSL is the core cryptographic library CloudFlare uses for SSL/TLS connections. If your site is on CloudFlare, every connection made to the HTTPS version of your site goes through this library. As one of the largest deployments of OpenSSL on the Internet today, CloudFlare has a responsibility to be vigilant about fixing these types of bugs before they go public and attackers start exploiting them and putting our customers at risk,” reported CloudFlare in official blog post.
It is crucial to upgrade every server using OpenSSL, the version 1.0.1g fix the flaw, previous versions of the library OpenSSL must be re-compiled with the OPENSSL_NO_HEARTBEATS flag solve the problem. Let me suggest you to see the following video realized by Zulfikar Ramzan, MIT Ph.D. and CTO of cloud security firm Elastica.
Numerous online services to implement it or TLS to encrypt traffic and transactions, the OpenSSL version 1.0.1g includes a fix for other kind of side-channel attacks.
Be aware, encryption notoriously id used to protect our privacy and sensitive data, this vulnerability could expose them!
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(Security Affairs – OpenSSL, Heartbleed)
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Text extracted automatically; images, tables and formatting may be missing. Original: https://securityaffairs.com/23808/hacking/heartbleed-bug-openssl.html